2.4 Statistical analysis
Descriptive statistics were used to organize and interpret patients’ baseline characteristics and comorbidities. Categorical variables are reported as frequencies (percentages), and continuous variables are reported as mean ± standard deviation or median (interquartile range). Categorical variables were compared using Fisher’s exact test or Pearson’s chi-square test, whereas continuous variables were compared using Student’s t-test and Wilcoxon’s rank-sum test.
The fluoroscopy and procedure times were modeled as cubic spline functions. The slope was calculated by differentiating the cubic spline curve with respect to the procedure time. A linear regression analysis was performed to confirm that the decrease in fluoroscopy and procedural time, followed by an increase in experience, was significant or not.
All tests were two-tailed with values of p < 0.05 considered as significant. Statistical analyses were performed using R programming version 4.0.3 (The R Foundation for Statistical Computing, Vienna, Austria).